How much should you invest at 4% simple interest in order to earn $50 interest in 6 months

Simple interest formula

Interest = Pit = $50

P=principal (initial investment)

i=annual interest rate = 0.04

t=time in years = 6 months = 0.5 years

Substitute values,

$50 = P*0.04*0.5

Solve for P

P=$50 / (0.04*0.5) = $2500